Nickel, titanium, cobalt, iron, and copper permanent magnet



Patented Jan. 18, 1938 UNITED STATES NICKEL, TITANIUM, COBALT,

corraa rsamxm IRON, MAGNET AND Kotaro Honda, Sendai, Japan No Drawing.

1933, Serial rial No. 735,898.

Original applications November- 13, No. 697,874, and July 18, 1934, Se-

Divided and this application June 6, 1935, Serial No. 25,343. In Japan May 6 Claims.

This invention relates to improvements in elloys for permanent magnets and more particularly tcan alloy consisting mainly of nickel, titanium, cobalt, copper and iron, and has for its object to provide a permanent magnet which has a very high' coercive force and long durability.

This forms a divisional from application Ser. No. 735,898 filed July 18, 1934 and also from the parent application Ser. No. 697,074 illed November 13, 1933, both pending.

Heretoiore commonly used magnet steels such as tungsten steel, chrome steel and the like have comparatively'small coercive force of only 60 to 70 gausses and it such alloy steels are used as a permanent magnet they lackdurability and are especially unsuitable for a'magnet oi. smaller dimension-ratio, that is, having a small ratio of the length and diameter. Moreover, such alloy steels are greatly ail'ected by temperature variations and mechanical shocks andshow unstable magnetic properties.

This invention is to obviate the above mentioned defects and to provide an alloy which is well adapted for a permanent magnet of a smaller dimension-ratio, and possesses stable magnetic properties for temperature changes andmechanical shocks and has particularly high coercive force.

The alloy of this invention can be obtained by melting together nickel, titanium, cobalt, copper and iron in the proportion of 3 to 50% nickel,

8.1% to 50% titanium, less than 60% cobalt, .1 to 20% copper and the remainder substantially iron. The preferred compofltion of the alloy may be oi 10.1 to 40% nickel, 8.1 to 40% titanium, less than50% cobalt, .l to 20% copper and the remainder iron. The'molten product may be cast N'lckel 11% 16% Titanium 10% 11% Cobalt 20% 28% lron Remainder Remainder Residual magnetlcinduction (gausses)..- 9000 7500 Coercive iorce ilausses) 260 880 The alloys of the present invention may also contain copper in the proportion of less than 20% to further increase the residual magnetic in- I duction and the coercive force.

Accordingly the alloy oi this invention is well adapted for the material of permanent magnets in general and more especially of smaller dimension-ratio and it has very stable structure at a temperature below about 700 C., and its magnetic properties are not substantially aiIected by the change of temperature and thus it is most suitable for the material of permanent magnets for fine instruments and also for heat resisting permanent magnets.

I claim:

1. An alloy containing about 11% nickel, 10% titanium, 20% cobalt, 0.1% to 20% copper, and the remainder iron and a small amount of impurities, characterized by a coercive force of about 250 gausses or more.

2. An alloy containing about 16% nickel, 11% titanium, 28% cobalt, 0.1% to 20% copper and the remainder iron and a small amount of impurities; characterized by a coercive force of about 830 gausses or more.

3. A permanent magnet formed of .an alloy containing 10.1% to 40% nickel, 8.1% to 40% titanium, 0.01% to 50% cobalt, 0.1% to 20% copper and at least 20% iron and a small amount of impurities, characterized by a coercive force in the neighborhood of 250 gausses or more.

4. A permanent magnet formed of an alloy containing 3% to 50% nickel, 8.1% to 50% titanium, 0.1% to 50% cobalt, 0.1% to 20% copper and at least 20% iron and a small amount of impurities, characterized by a coercive force in the neighborhood of 250 gausses or more.

5. For permanent magnets an alloy containing about 11% nickel, 10% titanium, 20% cobalt, 0.1% to 20% copper, and the remainder iron and a small amount of impurities, characterized by a coercive force of about 250 gausses or more. Y

6. A permanent magnet formed of an alloy containing about 16% nickel, 11% titanium, 28% cobalt, 0.1% to 20% copper and the remainder iron and a small amount of'impurities, characterized by a coercive'iorce oi about 830 gausses or more.

KOTARO HONDA. 

